To provide an axial piston motor, comprising at least one main burner, which has at least one main combustion space and at least one main nozzle space, and comprising at least one pre-burner, which has at least one pre-combustion space and at least one pre-nozzle space, wherein the pre-combustion space is connected to the main nozzle space by way of at least one hot gas feed, that has improved operating and control characteristics even under non-steady-state operating conditions, the pre-nozzle space of the pre-burner has at least one auxiliary hot gas feed.

A variable-displacement engine comprises an engine block, power shaft and rotating cylinder block. Pistons and connecting rods mounted in the cylinder block connect to a wobble plate having a rotating ring portion and non-rotating ring portion connected to allow relative rotation therebetween while constraining the portions to remain parallel. The wobble plate defines an inclination plane, pivot axis and wobble plate angle . A piston control mechanism includes axial lift, control lever supported by the lift and by an axially fixed anchor bearing, and links connecting the control lever to the wobble plate. Axial movement of the lift changes the axial position of the control lever pivot and changes the control lever angle, in turn changing, via the connecting links, the wobble plate angle and the axial position of the wobble plate pivot axis. This changes the piston displacement of the engine while maintaining substantially constant compression ratio.

The present disclosure relates to a zeroing device comprising a piston movable along an axis, at least one biasing member for biasing the piston along the axis, and an axially displaceable zeroing member limiting axial movement of the at least one biasing member. The present disclosure further relates to a variable displacement hydraulic unit including said zeroing device.

Devices and methods for improving the efficiency of an axial piston hydraulic motor or other axial piston hydraulic device. In some embodiments, a valve cam, with specified geometry, is assembled to a conventional axial piston hydraulic device (e.g., hydraulic motor, hydraulic pump, hydraulic pump-motor) in a manner permitting selective rotation of the valve cam relative to the distributor valves (e.g., spool valves). The rotating valve cam facilitates variable piston stroke and can be provided in conjunction with (e.g., joint control) an adjustable swashplate according to a mathematical relationship in order to adjust the displacement of the axial piston hydraulic motor (or other device) while maintaining optimal pre-compression and decompression across a range of operating conditions. This configuration allows, for each desired effective displacement of the hydraulic motor, a set of optimal valve timing to achieve perfect pre-compression and decompression so as to eliminate associated throttling losses.

Systems and methods for a variable displacement hydraulic motor. The hydraulic motor, in one example, includes a swash plate with a tilt angle, multiple piston assemblies configured to rotate about a drive shaft. In the motor, each of the piston assemblies includes an inner piston slideably coupled to an outer piston that mates with a cylinder in a cylinder block and a retainer device configured to inhibit axial movement of the outer piston in a first position and permit axial movement of the outer piston in a second position.

A shoe for use with a hydraulic piston motor or pump is disclosed herein. The shoe includes an upper portion configured to receive the hydraulic piston, a lower portion configured to contact a swashplate, a counterbore formed in the lower portion, a vertical channel extending through the upper portion and the lower portion into the counterbore, and a seal disposed within the counterbore and extending around a circumference of the counterbore.

A hydraulic device comprises an outer surface of a rotor rotating and facing an outer surface of a port member. The rotor has a plurality of cylinders disposed about an axis and cooperating pistons. The cylinders communicate with respective open ends at the rotor outer surface. Each open end alternatingly communicates with high and low pressure ports. Each two successive cylinders are interconnected via a fluid displacement member having first and second openings communicating with each respective cylinder and a closure element that obstructs either the first or second opening if the pressure in the cylinder that communicates with the second opening is higher or lower than the pressure in the cylinder that communicates with the first opening, respectively. The first opening and the second opening of each two fluid displacement members which communicate with one cylinder are fluidly connected with that cylinder at opposite sides of a flow resistance.

A closure element for a fluid end assembly that has two or more recessed grooves formed in its outer surface. The grooves are axially offset. A seal is placed in one and only one of the grooves. As wear occurs, the seal is relocated to one of the other grooves. Instead of a series of axially offset grooves in a single closure element, a kit may be formed from two or more otherwise identical closure elements, each with a single recessed groove at a different axial position. Another closure element has a series of ledge-like surfaces defining spaces within which a seal may be received. One outer surface surrounds one or more of the other surfaces. A seal is placed in one and only one of the spaces. As wear occurs, the seal is relocated to one of the other spaces.

A hydraulic piston motor/pump is disclosed herein. The hydraulic piston motor/pump includes a first rotor including a first cylinder, a second rotor opposing the first rotor and including a second cylinder that opposes the first cylinder, a first swashplate including a first angled face adjacent the first rotor, a second swashplate adjacent the second rotor and opposing the first swashplate, a first shoe cage including a first piston opening, a second shoe cage including a second piston opening, a piston configured to travel into and out of the first cylinder and the second cylinder, a piston shoe configured to engage the piston, the first shoe cage, and the second shoe cage, and a shaft engaging the first shoe cage and the second shoe cage and configured to rotate in response to a rotation of the first shoe cage and the second shoe cage.

A closure element for a fluid end assembly that has two or more recessed grooves formed in its outer surface. The grooves are axially offset. A seal is placed in one and only one of the grooves. As wear occurs, the seal is relocated to one of the other grooves. Instead of a series of axially offset grooves in a single closure element, a kit may be formed from two or more otherwise identical closure elements, each with a single recessed groove at a different axial position. Another closure element has a series of ledge-like surfaces defining spaces within which a seal may be received. One outer surface surrounds one or more of the other surfaces. A seal is placed in one and only one of the spaces. As wear occurs, the seal is relocated to one of the other spaces.